$ git clone -n https://github.com/xcp-ng-rpms/blktap /var/lib/mock/v8.3-u-mlr1-9859-28581/root/chroot_tmpdir/scmroot/blktap
Cloning into '/var/lib/mock/v8.3-u-mlr1-9859-28581/root/chroot_tmpdir/scmroot/blktap'...
$ git fetch origin a815cdf4371fc09730a751aa9f6eef9db08b17e5:KOJI_FETCH_HEAD
From https://github.com/xcp-ng-rpms/blktap
 * [new ref]         a815cdf4371fc09730a751aa9f6eef9db08b17e5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a815cdf bump release for test build